Decades after Zofran was introduced amid little knowledge of its effects in pregnant women, new research and reports are making information about Zofran side effects more readily available.

Zofran has been approved by the FDA as a treatment for nausea and vomiting associated with surgery and certain treatments used for cancer. The drug works by inhibiting the action of the neurotransmitter serotonin in a part of the brain that controls vomiting.

Zofran, also known as ondansetron, was introduced to the market in 1991. By 2015, it was being prescribed over 21 million times in the U.S., 10 times as often as it was prescribed in 2006.

When Zofran first entered the market, there was a trend in the scientific community toward avoiding research on the effects of drugs in pregnant women.

Both the scientific community and the public still had memories of the birth defects-generating drugs like thalidomide discovered in the 1960s and ‘70s.

Pregnant women were considered “vulnerable,” according to the National Institutes of Health. Expecting mothers themselves were often hesitant to agree to participate in research studies.

So at the time of the drug’s introduction, Zofran side effects had been studied in pregnant animals, but not in pregnant women.

Doctors nevertheless had discretion to prescribe Zofran for uses not specifically approved by the FDA, known as “off-label” use. It became a gradually more common practice for doctors to prescribe Zofran for morning sickness.

But although it’s legal for doctors to prescribe drugs off-label, it’s unlawful for the drug’s manufacturer to promote the drug for any use other than those approved by the FDA.

In 2012, a federal investigation culminated in a $3 billion penalty assessed against GlaxoSmithKline, in part over allegations that it had illegally promoted Zofran for morning sickness, without FDA approval for that use.

The U.S. Department of Justice alleged that GSK had made false representations about using Zofran for morning sickness and paid illegal compensation to doctors in exchange for their prescribing Zofran for that use.

Increasing Reports of Zofran Side Effects

At about the same time as the federal investigation, research studies had begun to show reports of birth defects associated with Zofran treatment. Researchers found increased risks of babies being born with cleft palate and heart defects.

Since then, hundreds of parents have come forward to file Zofran lawsuits seeking compensation for their children’s alleged Zofran side effects.

Several parents alleged the drug was responsible for their children having been born with anomalies like cleft palate, heart problems and kidney defects.

They cited the growing body of research, as well as hundreds of adverse event reports filed with the FDA.

One of the plaintiffs in these Zofran lawsuits says even though Zofran gave her good relief from morning sickness, she would not have taken it if she had known that it had not been specifically approved for prenatal use.

Marquita S. says that during her second pregnancy, she suffered from nausea and vomiting so bad she was missing work and having trouble getting out of bed. She tried Zofran on her doctor’s advice, and it worked so well she kept using it.

But five months into her pregnancy, an ultrasound revealed that her child’s heart was critically underdeveloped. Her son needed open-heart surgery only three days after he was born in April 2014.

Two months later he underwent a heart transplant. He has to take transplant drugs that interfere with his immune system. He has had trouble breathing and other problems that have required ongoing medical attention.